In Japanese Laid-open Patent Application No. 58-113901 (Patent Document 1), a method is given for predicting the amount of deformation due to the internal stress of a covering layer before a deposition layer has been used to cover an elastic substrate, and for deforming the substrate surface by that amount in the opposite direction in advance and preventing subsequent deformation and detachment of the layer.
In Japanese Patent No. 3639822 (Patent Document 2), in order to prevent detachment of a substrate and a covering layer, a method is given for providing an adhesive layer to the boundary surface between the two and forming the covering above into a multi-layered structure, whereby the internal stress of all of the layers is alleviated.
In Japanese Laid-open Patent Application No. 2006-053180 (Patent Document 3), an optical apparatus is given. The optical apparatus comprises an optical element having high transmittance across a wide bandwidth, wherein layers having high and low indices of refraction have been layered.
Japanese Laid-open Patent Application No. 2-252629 (Patent Document 4) discloses a method wherein a die is affixed to an optical element that has been hot-press molded to the net dimensions, whereupon heating is performed under applied pressure followed by cooling under low pressure so that the die can be removed with minimal complication and without compromising the structural precision.
In Japanese Laid-open Patent Application No. 60-246231 (Patent Document 5), graphite is used as the material for upper and lower dies used when press-molding a glass lens.
In “Precision Processing of Fine Ceramics” (Non-Patent Document 1), fine ceramics are ground and polished, whereby an altered layer is formed on the processed surface.
In “Optical Characteristics of a Dense ZnS Sintered Body Allowing Infrared Transmittance” (Non-Patent Document 2), the crystalline organization of a polished ZnS sintered body is given (p. 76, FIG. 8).
In “Techniques for Testing Optical Elements and Structures” (Non-Patent Document 3), a method is given for measuring the warping (measuring the surface deflection) of a lens.
[Prior Art Documents]
(Patent Documents)